print(13 + 15)
print(13.0 + 15.0)
print(15 / 3)
print(10 // 3)
print(10 % 3)
print(math.pi)
local tolerance = 10
function isTurnback(angle)
    angle = angle % 360
    return (math.abs(angle - 180) < tolerance)
end
print(isTurnback(-180))
print(2 * 1 ^ 3)